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Chevron Products Company Page 2 Chevron Station#9 617E 6633 Pacific Avenue Stockton Cahfomr, October 29 2001 • Subsurface Conditions Fill, sand-clay and sand-silt mixtures, and sands were encountered throughout the soil profile to depths of 84 feet below ground surface (ft bgs) Soil boring logs with well construction details for the installed wells are presented in Attachment C • Soil Sample Selection and Analysis. Two soil samples were collected for chemical analysis from each of the six shallow borings, one near the capillary fringe and one near the bottom of the borehole Three soil samples were collected for chemical analysis from the deep boring The soil samples were submitted to a California state-certified laboratory and analyzed for the presence of TPHg, BTEX, and the fuel oxygenates methyl tertiary butyl ether (MtBE), di-isopropyl ether (RIPE), ethyl tertiary butyl ether(ELBE), ethylene dibromide (EDB), tertiary amyl methyl ether (TAME), tertiary butyl alcohol (TBA), 1-2 dichloroethane (1,2-DCA), methanol, and ethanol Soil analytical results are summarized in Table 1 Certified analytical reports and chain-of-custody documentation are presented as Attachment D Monitoring Well Development. On July 12, 2001, SECOR personnel supervised Cascade Drilling, Inc in developing the monitoring wells Each well was surged over the length of the screen interval and then purged by removing approximately 10 casing volumes of water After well development, a groundwater sample was • collected from each well and sent under standard chain-of-custody procedures to a California State-certified laboratory The groundwater samples were analyzed for TPHg, BTEX, and fuel oxygenates (MtBE, EtBE, TBA, TAME, DIPE, 1,2-DCA, EDB, methanol, and ethanol) Groundwater analytical results were presented in Gettler-Ryan's third quarter 2001 monitoring report, dated August 10, 2001 Gettler-Ryan will continue to monitor and sample these wells on a quarterly basis along with the other wells located at the site • Well Abandonment. The 6-inch steel-cased well OW-I was abandoned by pressure grouting from the bottom up with a 2-inch PVC tremie pipe The well box was then removed and the area was finished to grade with cement • Stockpiled Soil. Approximately 25 cubic yards of soil generated during the installation of the wells were stored onsite in a lined bin Four samples of the stockpiled soil were collected by SECOR and composited into one sample by the laboratory to be analyzed for TPHg, BTEX, MtBE, and total lead On July 11, 2001, Integrated Waste Management of Milpitas removed the bin for disposal based on the results of the analysis of the composite sample Stockpiled soil analytical results are presented in Table 2 • Site Survey. On July 20, 2001, a California-licensed surveyor surveyed the existing and newly installed wells relative to the California State Plane coordinate • system to a horizontal accuracy of 0 1 foot and a vertical accuracy of 0 01 ft 11Chevron1961711REPORTS\siteassess9 6171 doc